forked from Minki/linux
d38afeec26
Originally, inet6_sk(sk)->XXX were changed under lock_sock(), so we were able to clean them up by calling inet6_destroy_sock() during the IPv6 -> IPv4 conversion by IPV6_ADDRFORM. However, commit03485f2adc("udpv6: Add lockless sendmsg() support") added a lockless memory allocation path, which could cause a memory leak: setsockopt(IPV6_ADDRFORM) sendmsg() +-----------------------+ +-------+ - do_ipv6_setsockopt(sk, ...) - udpv6_sendmsg(sk, ...) - sockopt_lock_sock(sk) ^._ called via udpv6_prot - lock_sock(sk) before WRITE_ONCE() - WRITE_ONCE(sk->sk_prot, &tcp_prot) - inet6_destroy_sock() - if (!corkreq) - sockopt_release_sock(sk) - ip6_make_skb(sk, ...) - release_sock(sk) ^._ lockless fast path for the non-corking case - __ip6_append_data(sk, ...) - ipv6_local_rxpmtu(sk, ...) - xchg(&np->rxpmtu, skb) ^._ rxpmtu is never freed. - goto out_no_dst; - lock_sock(sk) For now, rxpmtu is only the case, but not to miss the future change and a similar bug fixed in commite27326009a("net: ping6: Fix memleak in ipv6_renew_options()."), let's set a new function to IPv6 sk->sk_destruct() and call inet6_cleanup_sock() there. Since the conversion does not change sk->sk_destruct(), we can guarantee that we can clean up IPv6 resources finally. We can now remove all inet6_destroy_sock() calls from IPv6 protocol specific ->destroy() functions, but such changes are invasive to backport. So they can be posted as a follow-up later for net-next. Fixes:03485f2adc("udpv6: Add lockless sendmsg() support") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
87 lines
2.4 KiB
C
87 lines
2.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Definitions for the UDP-Lite (RFC 3828) code.
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*/
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#ifndef _UDPLITE_H
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#define _UDPLITE_H
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#include <net/ip6_checksum.h>
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#include <net/udp.h>
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/* UDP-Lite socket options */
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#define UDPLITE_SEND_CSCOV 10 /* sender partial coverage (as sent) */
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#define UDPLITE_RECV_CSCOV 11 /* receiver partial coverage (threshold ) */
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extern struct proto udplite_prot;
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extern struct udp_table udplite_table;
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/*
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* Checksum computation is all in software, hence simpler getfrag.
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*/
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static __inline__ int udplite_getfrag(void *from, char *to, int offset,
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int len, int odd, struct sk_buff *skb)
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{
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struct msghdr *msg = from;
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return copy_from_iter_full(to, len, &msg->msg_iter) ? 0 : -EFAULT;
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}
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/*
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* Checksumming routines
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*/
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static inline int udplite_checksum_init(struct sk_buff *skb, struct udphdr *uh)
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{
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u16 cscov;
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/* In UDPv4 a zero checksum means that the transmitter generated no
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* checksum. UDP-Lite (like IPv6) mandates checksums, hence packets
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* with a zero checksum field are illegal. */
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if (uh->check == 0) {
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net_dbg_ratelimited("UDPLite: zeroed checksum field\n");
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return 1;
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}
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cscov = ntohs(uh->len);
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if (cscov == 0) /* Indicates that full coverage is required. */
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;
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else if (cscov < 8 || cscov > skb->len) {
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/*
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* Coverage length violates RFC 3828: log and discard silently.
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*/
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net_dbg_ratelimited("UDPLite: bad csum coverage %d/%d\n",
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cscov, skb->len);
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return 1;
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} else if (cscov < skb->len) {
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UDP_SKB_CB(skb)->partial_cov = 1;
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UDP_SKB_CB(skb)->cscov = cscov;
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if (skb->ip_summed == CHECKSUM_COMPLETE)
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skb->ip_summed = CHECKSUM_NONE;
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skb->csum_valid = 0;
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}
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return 0;
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}
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/* Fast-path computation of checksum. Socket may not be locked. */
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static inline __wsum udplite_csum(struct sk_buff *skb)
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{
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const struct udp_sock *up = udp_sk(skb->sk);
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const int off = skb_transport_offset(skb);
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int len = skb->len - off;
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if ((up->pcflag & UDPLITE_SEND_CC) && up->pcslen < len) {
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if (0 < up->pcslen)
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len = up->pcslen;
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udp_hdr(skb)->len = htons(up->pcslen);
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}
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skb->ip_summed = CHECKSUM_NONE; /* no HW support for checksumming */
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return skb_checksum(skb, off, len, 0);
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}
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void udplite4_register(void);
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int udplite_get_port(struct sock *sk, unsigned short snum,
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int (*scmp)(const struct sock *, const struct sock *));
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#endif /* _UDPLITE_H */
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